Weather in Reykjavik in September

How September compares

September is the 4th warmest month of the year in Reykjavik. Against London's average high of 18.6°C in September, Reykjavik is 8.3°C cooler by day and 5.4°C cooler at night.

Daytime and night-time in September

The typical September day in Reykjavik peaks at 10.3°C, but that is an average: the warmest 10% of days reach 13.0°C or more. Days over 25°C are rare. Nights average 5.8°C; one night in ten drops to 2.0°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest September day here reached 17.0°C (2008-09-02) and the coldest night -2.1°C (1994-09-30).

Rain in September

Wet (more than 8 rainy days): about 18 days with 1 mm or more, 134 mm in total. Year to year it varies a lot - the wettest September was 2008 with 252 mm, the driest 2005 with 66 mm. Humidity averages 84%.

Sunshine and daylight

Around 2.8 hours of sunshine a day (estimated from cloud cover), 12.6 hours of daylight: the sun rises about 06:51 and sets about 19:55 local time in mid-September. Average cloud cover is 77%.

Is September a good time to visit Reykjavik?

September is not the strongest month here: cool days and frequent rain. The best months for Reykjavik on our scoring are June, May, July.

Cool days, with a sharper chill after dark

Plan on wearing layers throughout the day, rather than carrying a jacket just for the evening. Even the warmest 10% of days only reach 13°C or more, so a mild afternoon is still likely to call for something warm over a shirt. At the colder end, 10% of nights fall to 2°C or below: a warm outer layer, hat and gloves are sensible if you expect to spend time outside after dark. September suits travellers who prefer being active in cool conditions and do not mind dressing for them. The catch is that there is little reason to pack in expectation of summer heat, even around midday.

Enough daylight, but keep outdoor plans flexible

Rain is the main practical drawback. With about 18 rainy days, waterproof outerwear and footwear are more useful than an itinerary that depends on staying dry. That does not mean every wet day is a write-off, but it does make sense to leave room to rearrange outdoor time and take indoor breaks. There are about 12.6 hours of daylight, so September still gives you scope to be out during the day without relying on bright sunshine. Sunshine averages only about 2.8 hours daily, though, so daylight should not be confused with clear skies. Choose this month if you can accept damp spells as part of the trip, rather than something that would spoil it.